Manufacture of stencils for duplicating apparatus



- a material, such as castor oil, which will- Patented J Apr. 26, 1927.v

UNITED STATES P.ATE:NTI;.WOFFIICE.

PAUL canton, or mnY-sua-snmfrmcmassmnon moan. mcx comm,

or cnzcaco, more, a coaromrxou 01: rumors 'murac'rm or s'rmgcmsronnurLIca-rn m arrmarus.

no Drawing. Application m sc October is, 1923, Serial ms. scares, and inBelgium January 4, 1923.1

This invention relates to stencil-sheets for duplicating machines, suchas the mime? graph, and particularly to that type of stencil-sheetemploying an open, porous base, such as Japanese yoshino, coated with asolution'of soluble cotton in combination with combine with the cotton,a suitable solvent, such as alcohol, ether, acetone and the like,

being employed to dissolve the cotton and to aid in bringingthe/compound as a vwhole to the proper consistency for coating theyoshino in an approved manner, as, 1501' example, by immersing it in ordraWin' it over thesurface of the coating bath. 'gj he object of thepresent invention is to improve upon coating compounds of this generalcharacter in the direction of attaining greater flexibility, durabilityand impermeability.

Incarrying out the invention in an apsuch as yoshmo,-provided with atype-impressible coating including cellulose nitrate,

proved form, I employ, by way of exam Is, a El solution of collodion orcelluloi in a suitable solvent such as ether or alcohol ether (in thecase ofcollodion) or. acetone 'with or without ether or alcohol ether(in the case of celluloid), and with this I combine a suitable quantity,say approximately 40%, of castor oil. To the compound so constituted, Iadd a suitable quantity of a fatty substance, such as stearic acid orother suitable animal fat or acid, together with triacetin, or, in thealternative or in addition, an equivalentachemical of the same generalcharacter for the purposes of this invention, such as tartrate of butylor tartrate of amyl. The triacetin (or-its equivalent) acts in thecompound as anadditional softening agent and, more particularly, as aninternal lubricant facilitating the movementof that art of the coatingimpacted by the en the fatty vmonly own as stearic acid is used 'goodresults can be'obtained by the addition of approximately four' per centof this to the substance com-- Sept, 1923. coating comp0und.'triacetinorthe tartrates above mentioned, ap roximately three er centwill be found s cient Where a p I atty substance; such-as'l'stearicfacid is employed, should this develop .a tendency to crystallize, afterthe coating has been api plied to the sheet, Lpreferably' employ asuitable chemical such as benzilic alcohol,

having the effect in the compound of 'preoil,-a fatty substance andtriacetin.

4. A stencil sheet having aporous base, such asy'oshino, provided with atype-im pressible coatingincluding cellulose nitrate,

oil, a fatty substance of animal origin and triacetin.

5. A stencil sheet having a 'porous base,

such as yoshino, provided with a type-ink pressible coating includingcellulose nitrate, oil, a fatty substance, and a substance having theproperty of preventing crystallization of said fatty substance.

6. A- stencil sheet'having a porous base, such as yoshino, provided witha type-impressible coating including cellulose nitrate, oil and dibutyltartrate. a v

7. A stencil sheet having a porous base,

such as yoshino, provided with a type-impressible coating includingcellulose nitrate, o" di butyl tartrate and triacetin; v specificationsigned 22 day of PA-UL GAMPION.

